ACE inhibitor versus beta-blocker for the treatment of hypertension in renal allograft recipients

Angiotensin-converting enzyme (ACE) inhibitors have been shown to slow the progression of chronic renal failure. However, the value of ACE inhibitors for the treatment of hypertension in renal allograft recipients has not been established. ACE inhibitors dilate the efferent glomerular arteriole, an effect that may aggravate the decrease in glomerular filtration rate resulting from cyclosporine-induced vasoconstriction at the afferent glomerular arteriole. Therefore, the goal of this double-blind, randomized study was to compare the antihypertensive and renal effects of the ACE inhibitor quinapril with those of the beta-blocker atenolol in renal allograft recipients in whom hypertension developed 6 to 12 weeks after transplantation. All patients received cyclosporine as an immunosuppressant and had stable graft function (serum creatinine concentration, <220 micromol/L) at entry into the study. Twenty-nine patients who received quinapril (daily dose titrated between 2.5 and 20 mg) and 30 patients who received atenolol (daily dose titrated between 12.5 and 100 mg) completed the 24-month study. The two groups did not differ in age, sex ratio, height, and weight before entry into the study. Quinapril decreased diastolic blood pressure from 96+/-1 to 84+/-1 mm Hg (average throughout treatment period), and atenolol decreased diastolic blood pressure from 96+/-1 to 83+/-1 mm Hg. The serum creatinine concentration did not change significantly in either group after 24 months (129+/-8 micromol/L at entry and 148+/-19 micromol/L after 24 months in the quinapril group and 131+/-6 micromol/L at entry and 152+/-15 micromol/L after 24 months in the atenolol group; P=NS for both groups). After 24 months, the change in urinary albumin excretion from baseline was -10+/-15 mg/d in the quinapril group and 52+/-32 mg/d in the atenolol group (P=0.03). These results show that quinapril and atenolol are effective antihypertensive drugs when used after renal transplantation. Moreover, compared with atenolol, quinapril has no adverse effects on graft function. The relative reduction in albuminuria observed with quinapril as compared with atenolol could indicate a beneficial effect of quinapril on long-term graft function.